Roller conveyors using cylindrical rollers or spheres at the top surface of conveying belts are known. The function of the rollers may be accumulation of conveyed products on the moving belt with reduced back pressure, acceleration of the conveyed products, or diversion of conveyed products to either side of the conveyor belt for sorting purposes or for alignment along a guide. For diversion type applications, in most cases, the rollers are driven from underneath the running belt either passively by sliding the belt with the rollers over a support surface, or actively by driving them with another driven belt touching the rollers from the bottom side of the roller belt. Passive drive solutions are shown in the following patents and publications: U.S. Pat. Nos. 6,758,323; 7,191,894; 7,249,671; WO 2007/108852.
In FIG. 6 of WO 2007/108852, parallel longitudinal cylinders are disclosed as an alternative driving support surface. Such cylinders are used in both passive (non-driven) and active driven function in the following patents and publications: U.S. Pat. Nos. 7,237,670; 7,249,669; 7,344,018; and US 2008/0023301. In addition to rollers on the top surface of the belt, balls or spheres can be used for the same purpose as well. As shown in the U.S. Pat. No. 5,238,099; balls may be driven by a conveyor belt disposed in contact with the balls from underneath the belt.
There is a need for a system that reduces the distance between the spheres to improve the support of smaller products during conveying and that reduces the number of cylinders per belt to reduce the cost.